1. Field of the Invention
The present disclosure relates generally to data storage systems, and more particularly to a solid state blade-based storage system and methods of use and operation.
2. Description of Related Art
Current generation data server architectures are optimized for data stored on rotating media such as hard disk drives. Hard disk drives have very high latency in the order of milliseconds, relatively slow read speeds, and a random IOPS (Input Outputs per second) on the order of few hundred IOPS. To achieve higher performance with such systems, a single file must be distributed over multiple hard disk drives using a complex controller, commonly known as a RAID (Redundant Array of Inexpensive Disks) controller. When a file or set of data needs to be assembled, the RAID controller determines the “striping” and/or “mirroring” pattern used to distribute the file, and issues multiple respective requests to multiple drives for the portions of the data held on those drives. The RAID controller then assembles the data supplied from the individual drives. Seek time latency is unchanged by RAID—thus such a system may have random IOPS performance, for small unfragmented files, not much better than a single drive. The use of multiple high-speed disks also decreases the mean time between disk failures for a single distributed file; additional disks must be included to provide fault tolerance. The RAID system is also quite energy inefficient—significant computational demands are placed on the controller and the hard drives must rotate at high speed to boost performance.
FIG. 1 illustrates a block diagram for a traditional large storage system. Storage shelves 102, 104, 106, 108 are rack-mounted units. Each storage shelve may consist of a JBOD (Just a Bunch Of Disks), or may house multiple disk drives and possibly a RAID controller, appearing as a different disk configuration than its actual physical configuration. A storage head 110, also a rack-mounted unit, interfaces between a network and the storage shelves, and may include a RAID controller or simple single mapping of data to disks. On the network side, network ports connect storage head 110 to networked clients (not shown) over a network (e.g., Ethernet, Fiber Channel). Storage head 110 and the clients cooperate using a standard protocol, such as a NAS (Network-Attached Storage) protocol for file-based access or a SAN (Storage-Area Network) protocol for block-based access. A complicated interconnection 120, involving cables and/or optic fibers, and a dedicated ring or hub network, connects the shelves, which are distributed in one or more racks. The cables and attendant transponders between the shelves provide additional common points of failure, incorrect provisioning, or inadvertent disconnection.